CDM-2.0 (Climatological Dispersion Model-Version 2.0) determines long-term (seasonal or annual) quasi-stable pollutant concentrations in rural or urban settings using average emission rates from point and area sources and a joint frequency distribution of wind direction, wind speed, and stability. The Gaussian plume hypothesis forms the basis for the calculations. Contributions are calculated assuming the narrow plume hypothesis, and involve an upwind integration over the area sources. Computations can be made for up to 200 point sources and 2500 area sources at an unlimited number of receptor locations. The number of point and area sources can be easily modified within the code. CDM-2.0 includes the following options: 16 or 36 wind-direction sectors; stack-tip downwash; and gradual (transitional) plume rise. The user has a choice of seven dispersion parameter schemes. Optional output includes point and area concentration rises and histograms of pollutant concentration by stability class. Software Description: The model is written in the FORTRAN programming language for implementation on an IBM 3090, VAX 8650, or SUN 386i computer. The software is distributed on a 5 1/4-inch IBM PC-compatible diskette. Data is in compressed format but a dearchive utility is included.